Their One Year Mission: To boldly find the effects of null G on humans

NASA and Roscosmos have decided on two veteran 'nauts for a prolonged one-year-long mission on the International Space Station.

The Russian and US space agencies want to put a pair of spacefarers on the station for a prolonged duration to get more data on the effects of weightlessness on humans.

NASA's Scott Kelly piloted space shuttle mission STS-103 back in 1999 and commanded or served on three other space flights, logging over 180 days in space so far.

Cosmonaut Mikahail Kornienko was a test candidate on Russian rocket Energia in 1998 and trained as an ISS backup crew member before getting to go to the station in 2010. He nearly matches Kelly for time in space, having logged 176 days off Earth.

Boffins have already figured out a fair bit about how time in space affects people from the crew members on the ISS: from data on the effects of microgravity on bone density, muscle mass, strength, vision to other aspects of human physiology.

Spending a full year on the station will add to that scientific data and help with planning for future missions to the moon, an asteroid and eventually Mars, NASA said.

The two 'nauts will train for two years before setting off for the station in 2015. ®